The uncanny correlation between altitude and language development.

When University of Miami linguist Caleb Everett plotted nearly 600 of the world’s languages on a map using Google Earth, he noticed something peculiar: Languages containing a consonant sound known as an “ejective” (found in about one-fifth of the world’s languages) were clustered at or near high-altitude regions. From the Rocky Mountains of North America to the Caucasus of Eurasia to the Ethiopian Highlands, a clear correlation emerged between a specific speech sound and geography. But is it all just a remarkable coincidence? Listen to Mike Vuolo’s conversation with Everett, who offers what he believes to be a couple of plausible explanations.